Drawing machine



March 3l, 1953 l.. R. BERKEBIL DRAWING MACHINE 2 SHEETS--SHEET l R Ilo no`. .w .A Q t m 5 7 Filed Sept. 9, 1947 Tn i b mx QNR IN V EN TOR. ff R.BER/(EBM.

N R 0 .n M

Vl B 3 2 m mw. 3 E m H o 2 www@ m... W m M E uw m m w B4 G l R. M Q` JQs il# m L m S y \1 v/ mw. Jmvl//MM #lll/IIIA: M m0 \m 4 l uw A 9fw/.vvd m V v/ u m, t u. h m m w W M m L w Patented Mar. 31, 1953DRAWING MACHINE Lee." R'.. Berkebil, Detroit, Mich., assgnorl toi Na.-

tionalA Steel: Corporation, a corporationof. Delai` Ware.

pnlicatioxr September 9, 194'?, Serial No. '772;9'45

'l Claims.

The present invention relates toa@ method of and apparatus fordrawingrods` inv which.` lengths of Wires, rods, bars, or the like,hereinafter collectively referred to as 'rods,l are drawnthrough a dietoireduce or form the rods tothe desired: size" or shape.

As used herein, they terms ndrawn, drawing and the like are used toindicate that as the rod is moved through the die thevl rod is reducedinA size or formed to the desired shape. These terms are not limited toWhere the rod is pulled through the die and include those methods andmachines where the rod is pushed through the die while being drawn. i

In some rod drawing machines, the leading end is pointed or is formedin. a reduced size so that' it can be freely pushed through the die. Thepresent invention is only concerned? Withwherethe rod isdrawn, that is,reduced in size or formed to the desired size or shape, upon beingypushed through the die.. For various reasons, the for-- ward or leadingend portion of a rod upon being pushed through the die will at timesbend later ally away from the wire lineof' the machine; The bending ofthe rodsmay be causedhbyimperfections in theV die or mayv be' causedy byvariations or imperfections` in the different rods.. or thev bending mayresult from the combination of these factors. Where imperfections inHthe die cause the rods to bend when pushed through the' die,v theL rodslwill bend in the same direction. Bent rods; may notv be properly drawnand may cause damage tothe machine and it usually isl necessaryt'o'd'iscard` or reprocess these bent rodswhich is uneconomical. As apractical matter, it is veryf dimc'ult, if not impossible, to constructdies so perfectly that they rodsV do not bend a. slightr amount and aslight amount of' bending which is not sufiicient toI interfere With`subsequent opera-` tionsusually requires that thel rods bei straight-lcned.

-i's 'anobfject ofi the present. invention to providsa method of andapparatus for drawing rods that will reduce or prevent the. rods frombending out of shape. i

' Another object ofv thepresent invention is to provide a methodof andapparatus for drawing rods which theend portionsof those rods- Whichbendor tend to bend upon being pushed through the die as aresult ofimperfections in the diew-ill be straightened', either substantially orperfectly, as the rods are pushed through. the die.

A further' object of the` present invention is to provide a metho'dvofiand apparatus for drawing;

tendto bend and that will not deform those. rods which do not tend1 tobend.

Itis also. an objectof thei present invention to provide' a rodi drawingmachine including rod; straightening means that is automaticallyproperly positioned.

In accordance vvith` the present invention, a, rod ispushed through thedie and. if the rod bends as a` result of4 imperfections in the die,.itiI is straightened as the rod. is advanced through the die. In a roddrawing machine embodying the. principles' of the present invention, adie positioned so that those rods tending toV bendr as aresult of dieimperfections,V which may' be all. oru part of the rods being. drawn,will tend. to bend inthe same predetermined direction.. A rodvstraightening devicev is provided on` the' exit side. of the die. andthis devicev includes a guide which engages the rod and bends it`substantially straight as the end portion is being; pushed. through the.die by thev push carriage. l5?referablyf,l the rod'straightening.` guideis; sot positioned as to bend the end portion of. the rod'` a slightamount beyond the straight condition. so that the stresses: setz up inthe rod bythe die will be entirely overcome.l It'. is. neces'- sary tobend the" rod. only slightly beyond the straight condition as. the:stressesV and strains caused. by the die. are readily overcome and.the:` rod at this time has: only a relatively small amount of"springbaclr. If the rod were not straightened until later when themetalhasage hardened, it would bei very' difficult toA straighten therod and it Would benecessaryto use relatively quite heavy equipment.With the guide posi-v tioned-either to bend and-` maintain the rod sub--stantially or perfectly straight as it leaves the die or positioned tobend the end portion laterally and slightly beyond the straightcondition', the end portion of the rod is bent by the guide in adirection opposite to the direction` the die bends" the rod. tostraighten. the rod. Ciani means may be provided to automatically movethe guide into and out` of the rod straighteningr position. By

. means of. the present invention, the. production.

ofY the. bent rods as ay result of imperfect dies is substantially orcompletelyl eliminated.. The rod'. straightening guide does not bendstraight rods suiiiciently to deformthem.

I'Ihese and other objects andadvantages of the present invention willbecome more readily `ap parent from' the following detailed description,taken in connection thek accompanying drawihgsfin-Whichz' reds'thaise-wm. straight-en out tnosercds which 551 Figur 1 is a pian View!of rod drawing inabox 38 to the hydraulic motor 3|.

chine embodying the principles of the present invention;

Figure 2 is a side elevational view of the machine of Figure 1 withportions of the supporting structure removed;

Figure 3 is an enlarged, fragmentary longitudinal sectional view of partof the machine of Figure 2; and,' l

Figure 4 is an enlarged, fragmentary view taken substantially along line4--4 of Figure 3.

Referring to the drawings, the rod drawing machine includes a draw benchI on which is mounted in a fixed position a die holder 8. Apower-actuated push carriage `9 is slidably mounted in ways I formovement forwardly and rearwardly along bench I toward and away from thedie holder. Carriage 9 advances the leading end portion of a rod 24through a die Ii removably retained in holder 8 by plate I3 upon eachforward stroke toward the die I I. A poweractuated pull carriage I2 issupported on bench 'I for forward and rearward movement away from andtoward the die holder 8 to pull a rod through die II upon each forwardstroke away from die holder 8. Thus, as willbe more fully hereinafterdescribed in detail, the push carriage 9 pushes the leading end of a rod24 through die II and then pull carriage I2 engages the leading end ofthe rod and pulls it the rest of the way through the die. The rod isdrawn by the die both when it is being pushed and when it is beingpulled through the die.

The present rod drawing machine is constructed and arranged for drawingthree rods simultaneously. There are three identical dies in holder 8and three identical rod gripping mechanisms in each carriage. Thosemechanisms cooperating to draw one rod will be described in detail, itbeing understood that these mechanisms are duplicated for each rodsimultaneously drawn Aand that it is immaterial whether one or aplurality of rods are drawn.

Carriage 9 Vis connected to the outer ends of pistons Il of a pair ofhydraulic cylinders I8 connected throughsuitable .valves (not shown) toa source of fluid under pressure. A` jaw holder I5 is removablymounted.` in a pocket I6 of carriage 9. As shown more clearly in Figure3, in the-holder I 5; there are -a pair ofgblocks `I Ihavingtapered,-opposed inner surfaces. A pair of rod-gripping jaws I8are movably mounted in blocks II with ball bearings I9 disposedtherebetween. Springs 2I urge the'jaws I8 toward the right and inwardlytoward the wire line 23 of the rod drawing machine. The springs 2|permit limited, spreading movement of jaws I8 toward the left so that arod can be pushed manually between the jaws and toward the die II. Whenthe carriage 9 moves toward the left and toward the die II, the jaws I8'are wedged against and tightly grip the rod 24 and force its leading endportion 25 through the die. When the carriage 9 is withdrawn toward theright away from die II and along theways I0, or when the rod 24 ispulled through the die I I by pull carriage I2, the grip of jaws I8 onrod 24 is loosened sunciently to allow the rod 24 to slide through thejaws.

The pull carriage I2 is mounted on two pairs of rollers 26 for movementalong rails 21 toward and away from the die II. The carriage I2 isinrengagement with a pair of lead screws 29, each of which is connectedthrough a gear train When the hydraulic vmotor 3l rotates, the lead yscrews 29 rotate to move the carriage I2 toward or away from the die IIdepending upon the direction of rotation of the lead screws.

A pair of rod gripping jaws 32 are mounted in a pair of blocks 33 withball bearings 35 disposed between their tapering surfaces. Springs 36resiliently urge jaws 32 inwardly toward the right into engagement withthe-rod end portion 25. As the Ycarriage I2 is moved toward the rightand approaches the position shown in Figure 3, the jaws 32 can spreadsufficiently to slip over the end of rod 24. When the carriage I2 isthen moved toward the left to the position shown in Figures 1 and 2,the' jaws 32 are wedged into engagement with the rod and pull it throughthe die II. The greater the resistance of movement of the rod throughthe die, the more securely jaws 32 and jaws I8 grip the rod.

-The above described combination of die and push and pull carriagescontaining releasable rod gripping jaws forms no part of the presentinvention and other types of push and pull carriages and otherarrangements of rod gripping means and dies may be used. The presentinvention is not limited to the rod drawing machine shown herein and isapplicable to other types of rod drawing machines, such as headers, inwhich the rod is advanced through the die solely by being pushed.

Referring more particularly to Figures 3 and 4, the rod gripping jawsI3' and 32 and the die II are all disposed along and symmetricallyarranged about the wire line 23 of the rod drawing machine. When the rod24 is drawn properly without distortion, it is moved through the machinewith its longitudinal axis coinciding with the wire line 23. Themovement of both carriages is parallel with this wire line. As the pushcarriage 9 advances, the leading end portion 25 of rod 24 through dieII, portion 25 is unsupported as it emerges from the die. At least attimes, the leading end portion A29 will bend laterally away from thewire line. At times it may be possible to construct and arrange the dieso that none or substantially none of the rods bend, but if a dierentdieis substituted, the rods may bend. "With any particular die, it hasbeen found that those rods which are caused to bend by the die will allbend in the same direction. i

1 In accordance with the present invention, a rod straightening deviceshown generally at 38 is provided for straightening the end portions 25of those rods which normally bend laterally away from the wire line 23as a result of stresses set up in the rod by the die without distortingor deforming those rods which do not tend to so bend. A rodstraightening device 38 is provided for each die I I. As these devicesare all similar, only one will be described in detail. The die II isturned so that those rods which do bend, bend downwardly. A rodstraightening guide or roller 39 is rotatably mounted on a pin 49supported in a bracket 4I vertically, slidably mounted in ways 43 ofretainer members 44. A lower member 45 is also vertically slidablymounted in ways 43 below bracket 4I. A screw 46 is adjustably mounted inlower member 45 with its head 4l engaging bracket 4I for adjusting thevertical position of roller 39. A set screw 49 is provided in member 45for locking screw 46 in the proper position. The lower side of dieholder 8 is slotted at 5U to receive a horizontally movable cam 5I. Cam5I is held in place by plate 52 bolted to thebottomof die holder 8,.;Cam .5I includes a gee-ases i lower camsurface 53 and an upper camsurface 54 and extends through a slot 55 in lower member 45 so thatmember 451 and bracket 44 are supported on either cam surface 53 or camsurface 54. The cam 5I includes an elongated recess 51 containing aspring 58 and closed by a threaded plug 59. The opposite end ISI) ofrecess 5-1 is of reduced size and has slidably mounted therein anelongated pin 6I. A ball 62 is Ainterposed between the rear end of pin6I and spring 58. A slot 63 is formed in the outerend portion of pin- 6Ifor receiving the end of a stop pin 64. Pin 54 limits movement of pinV5I toward the left. Stop pins 65 and 61- 'are mounted in cam 5| andserve to limit the movement of the cam relative to holder 8.

Cam 5I projects beyond the die holder 8 toward push carriage 9 so thatwhen they push carriage 9 is moved toward the die holder to push theleading end 25 of the rod 24 through die II, the carriage 9 pushes thecam toward the left. This movement of the cam 5| brings surface 54beneath member 45 and raises roller 39 into position to engage thebottom surface of the rod to straighten and prevent the leading endportion 25 fromV bending downwardly and laterally away from wire line 23asl itis pushed through the die. The straightening device, andespecially screw 46 and. roller 39, are preferably so arranged that whenthe cam raises the roller 39 to thev operating position, the roller 39bends the leading end portion of the rod upwardly and slightly beyondthe wire line 23 so as to overcome the` stresses and strains set up inthe rod by the die. should be bent upwardly beyond the wire line. willdepend on a number of factors including the magnitude of the stressescaused by the die. At times, it may be. desirablev to have cam 5I andscrew 46v so proportioned and arranged that the roller 39. only israised far enough to bend the leading end portion of the rod upwardlysufiiciently to maintain the end portion straight as it emerges from thedie and preventgit from bendingV downwardly away from the wire: linewithout. bending the rod portion 25 upwardly beyond the Wire line. Withthe roller 3,9 in either positiony and if the die tends to bend the roddownwardly as it is. pushed through-'the die, the roller tends to bendthe rod upwardly and straighten the rod. Y

When the pull carriage I2 is moved toward the die. II to the positionshown in Figure 3-, it engages the end of pin 6I and pushes cam 5|toward the right to the positions shown. As carriage I2 approaches theleading end portion 25 of rod 24, portion 25 normally will be at leastThe amount that rod portion 25 6T then the roller 39- need not be andpreferably is not moved downwardly away from the rod until the end of`the rod has entered passage 68 and.

between jaws 32; Normally, it will not be necessary or desirable to bendthe rod end up far enough so it cannot enter passage S8.

A long bolt is mounted i-nholder 8. with its lower end 1| extending intorod passage 12 on the exit side of die H. The end 1I of bolt 10 ispositioned above thevwire line 23 a distance substantially equal to theradius of rod 24. When the rod straightening roller bends the endportion upwardly to straighten this portion, the rod engages the end 1Iof bolt 10 to provide a three point support for bending the end portionstraight. Whenbending an elongated member, a three point support isbetter than a two point suport. The bolt end` 1| prevents all bending ofthe rod taking place adjacent' the die I I. The

l bolt end 1|- preferably is slightly spaced above rod 24 Vso that itdoes not deface the rod as the pull carriage pulls the rod through. thedie. A1- though bolt end 1I may touch rod 24 at all times, it should notexert enough pressure on the rod to deface the rod. When cam surface 54raises roller 39 only far enough to bend the rod end upwardlysufficiently to maintain the end portion 25 straight and prevent the rodend from bending downwardly, theend of'bolt 10 aidsl in bending andmaintaining portion 25 straight.

A complete cycleof operation will? now be described, it being understoodthat control apparatus of any type can be used to automatically controlthe operation of the cylindersV I8 and motor 3| or cylinders I8 andmotor 3| may be manually controlled. At the start of the cycle,carriages 9 and I2 are in the position shown in FiguresV l and 2. Figure3falso shows carriage 9 in position at the start of acycle of operation.Three rods 24 are each insertedv through a corresponding guide 1S at theright hand end of the close enough to being in alignment with the wireline 23 so thatV the end of the rod will enter between jaws 3'2. If thestraightening device 38 including cam 5| is so constructed that the rodstraightening guide or roller 39 bends the vend of the rod upwardly andbeyond the wire line suiiiciently so that the rod' endA will not enterthe. guide passage 68, then cam 5I must bemoved toward `the rightsufficiently to lower roller 39A tothe inoperative position before theend of rod- 24 starts to enter the passage 68' leading to jaws 32. Whenthe rod straightening deivce 38 and cam 5I. are soconstructed andarranged that the roller 39 maintains the forward end portion of the rodin a substantially straight horizontal line or only bends the rod endupwardly beyond the wire line such a slightv amount that the rod endAenter Vpassage 68 and between-'thel"jaws` 32,-

machine and manually pushed through a guide 14 on carriage 9 toward thedie I-. The forward end 25 of the rod is manually pushed between jawsI8" and pushed-forward until the end is against die II. Fluid underpressure is then admitted to the head ends of cylinders I8 to Y movecarriage 9 along waysv l0' from its position shown in the drawingstowardl the die II. As carriage 9 moves toward the die, it first strikescam 5I and thenv moves it toward the'left to move cam surface 54 beneath.memberl 45 and raise roller 39 to the operative position. This movementor rst stroke of the carriage also moves the leading end portion of therod through die II for a short distance. The ow of fluid to thecylinders I8 is then reversed and the cylinders move the carriage 9toward the right and farther to the right than shown in the drawings.The cylinders I8 thereafter move the carriage 9 forwardly toward theleft to the position shown in the drawings'. This last forward strokemay be repeatedv a number of times as the carriage 9 pushes'the rodthrough the die II, the roller 39 bends the leading end portion upwardlyto straighten the rod and preferably bends the leading end slightlybeyond the through the die II, motor 3|I is started to rotate leadlscrewsf 29- and move thev carriage-I2 Vfrom its position shown inFigure 1 toward its p0- sition shown in Figure 3. As carriage I2appreaches die II, the carriage strikes the end of pin 6I and moves cam5I toward the right to its initial position shown in the drawings. Whencam 5I has been moved as far as pin B6 will permit any continuedmovement of carriage I2 will cause pin 6I to compress spring 58 whichalso acts as a safety means in the event carriage 9 is not properlylocated. Before roller 39 is lowered, the straightened end portion 25which is preferably bent upwardly and slightly beyond the horizontal isnearly enough aligned with the guide passage 68 so Lthat upon movementof carriage I2 toward die II, the rod enters passage. When carriage I2reaches the position shown in Figure 3, the rod end is between jaws 32and roller 39 has been lowered and the motor 3I is reversed to move thecarriage I2 to the left to the position shown in Figure 1. As carriageI2 moves to the left, jaws 32 grip the rod and pull it through die II.As the rod is being pulled by carriage I2 it is immaterial whether ornot the rod tends to bend downwardly as it will be pulled straight. Whenthe rod 24 has been completely drawn, it is removed from jaws 32 and thecycle repeated.

If cam surface 54 is of such a height or if screw 46 is so adjusted thatroller 39 merely holds the rod end portion 25 horizontal or bendsportion 25 slightly beyond the horizontal as it is pushed through thedie II, then the length of pin 6I preferably is such that the rod entersguide passage 68 and preferably between jaws 32 before the roller 39 islowered. When roller 3B is positioned to bend the rod end upwardly pastthe wire line suiiciently so that the end portion cannot enter passage68, then pin BI is of such a length that roller 39 is lowered before therod end enters passage 68.

I prefer to have the roller 39 bend the end portion slightly beyond thewire line so as to more nearly perfectly straighten the end portion bymore nearly completely overcoming the stresses set up in the metal bythe die. The degree to which the end portion is bent beyond the wireline will usually be very small but will depend at least in part on theproperties cf the metal and the characteristics of the die.

When drawing rods other than rounds, such as, hexagons, it is desirableto have a flat surface on top to be engaged by bolt end II Consequently,it may not be possible or desirable to position die II so that the rodstend to bend vertically downward and it may be necessary to position thedie I I so that the rod end bends downwardly and slightly to one side ofvertical. Pins 'I5 are provided in holder 4I for laterally positioningroller 39. Usually pins 'I5 are positioned to align roller 39 directlybelow the rod, but when the rod end tends to bend downwardly andlaterally, then pins I5 can be shifted to shift the roller 39 laterallyso that the roller Will bend the rod end upwardly and laterally in theopposite direction.

When it is necessary to change the die, the new die first is fastened inplace in the die holder. After one or more rods have been drawn, it willbe apparent in which direction the new die causes the rods to bend andthe new die can then be turned, if necessary, to cause subsequentlydrawn rods to bend downwardly. In those instances when the rods do nottend to bend even a slight amount as a result of die imperfections, thes traignte11-ing` deviceY wm not deform the rods.

Straightening the rod end portion 25 immediately after it passes throughthe die has been found to be much easier and better than straighteningthe end portion at a later period. When the rod is straightenedimmediately after being drawn through the die, age hardening of themetal which follows a colddrawing operation has not taken place and itis relatively easy to straighten the rod and overcome the stress andstrains caused by the die. Age hardening of cold drawn rods isrelatively rapid and apparently is-accelerated by the heat generatedwhen the rod is drawn. If such a rod is bent while being drawn, it willage harden so that by the next day relatively heavy straighteningequipment will be required to straighten the rod.

I claim:

l. In a rod drawing apparatus having a straight draw line, thecombination comprising, a bench, a die having an entrance side and anex' side disposed in a xed position along the draw line on the bench, apush carriage movable along the bench toward and away from the entranceside of the die for advancing the leading end portion of a rod throughthe die upon movement toward the die, said die having a tendency to bendthe leading end portion of the rod laterally in a direction away fromthe draw line, a pull carriage on the exit side of the die movable alongthe bench toward the die into an engaging position with the leading endportion of the rod which has been advanced through the die and movableaway from the die to draw the remainder of the rod through the die, rodstraightening means disposed adjacent the exit side of the die, supportmeans for mounting the straightening means for movement into and out ofan operable position in which the straightening means engages theleading end portion of the rod to straighten the end portion upon beingbent when the rod is being advanced through the die, and actuating meansfor moving the straightening means into the operative position duringmovement of the push carriage and out of the operative position duringmovement of the pull carriage.

2. The combination of claim 1 in which the actuating means includesmeans operable responsively to movement of the push carriage toward thedie to move the straightening means into operative position and meansoperable responsively to movement of the pull carriage to move thestraightening means out of operative posiion.

3. The combination of claim 1 in which the actuating means includes cammeans actuated by means responsive to movement of the push carriagetoward the die to move the straightening means into operative positionand by means operative responsively to movement of the pull carriagetoward the die means to move the straightening means out of operativeposition.

4. The combination of claim 1 in which a member is disposed along thedraw line between the rod straightening means and the die in position toengage the surface of the leading end portion only when the rodstraightening means bends the leading end portion beyond the draw line,such member then consituting the sole point of contact of the leadingend portion with the apparatus between the die and the rodstraighteningL means.

5. In a rod drawing apparatus having a straight draw line, thecombination comprising. a bench,

a die having an entrance side and an exit side disposed in a fixedposition along the draw line on the bench, a push carriage movable alongthe bench toward and away from the entrance side of the die foradvancing the leading end portion of a rod through the die upon movementtoward the die, said die having a tendency to bend the leading endportion of the rod laterally in a direction away from the draw line, apull carriage on the exit side of the die movable along the bench towardthe die into an engaging position with the leading end portion of therod which has been advanced through the die and movable away from thedie to draw the remainder of the rod through the die, rod straighteningmeans disposed adjacent the exit side of the die. the rod straighteningmeans being operable to engage the leading end portion of the rod toprevent the end portion bending when the rod is being advanced throughthe die by the push carriage, and a member disposed along the draw linebetween the rod straightening means and the die in position to engagethe surface of the leading end portion only When the rod straighteningmeans bends the leading end portion beyond the draw line, the memberthen constituting the sole point of contact of the leading end portionwith the apparatus between the die and the rod straightening means.

LEE R. BERKEBIL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 191,100 Braukman et al. May 22,1877 524,504 Robertson Aug. 14, 1894 524,508 Robertson Aug. 14, 1894637,466 Jernberg Nov. 21, 1899 886,717 Moltrup May 5, 1908 1,298,999Moltrup Apr. 1, 1919 1,940,354 Kerr Dec. 19, 1933 2,154,392 BarnhartApr. 11, 1939 2,155,437 Moore Apr. 25, 1939 2,199,602 Wright May 7, 19402,360,746 Walker Oct. 17, 1944 2,363,406 Ferrier Nov. 21, 1944 2,404,234Kerr July 16, 1946 2,434,006 Nye Jan. 6, 1948 2,492,544 Vetter Dec. 27,1949

